Culvert



April 26, 1938. R. A. BRADLEY GULVERT Filed April 8, 1956 2 Sheets-Sheet l April 26, 1938. R. A. BRADLEY 2,115,190

CULVERT Filed April 8, 1936 Sheets-Sheet '2 Patented Apr. 26, 1938 CULVERT RobertA. Bradley, St. Catharines, Ontario,

, Canada 'Application April 8, 1936, Serial No. 73,341 11 In Canada April 18,- 1935 7 Claims. (]..61-16) This invention relates to a development for the prevention of excessive wear on culverts; particularly culverts extending between lock chambers and having sharply descending portions therein. g e

An object of 'the present invention is te -cause a back pressure in the culvert; particularly many sharply inclined portion thereof in order to preventthe formation oiavacuu'm which is a'factor in causing continual 'wearingof the culvert wall. It is'known that as much as 18 inches of conorete in a culvert have been'ea'tenaway in one year due'to the forming of vacua therein.

It has been found that-in a culvert having a sharply inclined portion, water dropping freely therein accelerates at the rate of approximately 32.2 feet per second, causing the water to; leave the wall of the culvert near the bottom of the descending: portion,thus'forming a vacuum between the stream of'water andthe wall of the culvert. The pressure'on the stream is relieved at the point where, the vacuumis formed and, therefore, the air mixed in the water explodesout of it and, combined with the rarefied air of the vacuum, attacks the side of itheulverti The air thus separated from'the water 'i s carried along by the stream but does not mix with .11; again and, consequently, it accumulates underpressure at the top of the culvert and when the valves are closed a tremendous surge is producedby this trapped air which is quite liable to damage the lock equipment. Even when the air isnot trapped in the culvert wnen the valves are closedvacua therein cause an oscillation'of'the water which is called water hammer.

Another object of this invention is the prevention of water hammer in culverts.

With these and other objects in view the invention consists essentially of a constriction placed in a culvert having a sharply descending portion, and one or more additional constrictions .spaced along the lower portion of the culvert,

as more fully described in the following specification and illustrated in the accompanying drawings, in which Figure 1 is a longitudinal section taken through a culvert extending between two lock chambers.

Figure 2 is an enlarged section taken on. the line 22 of Figure l. 1

Figure 3 is an enlarged fragmentary sectional view taken on the line 3-3 of Figure 1.

Figure 4 is a cross section of a lock chamber, showing the position of the culverts in relation to a lock chamber.

Figure 5 is an enlarged section taken on the line 5-5 of Figure 1.

Figure 6 is an enlarged section taken on the line 66 of Figure 1.

Figure? is a fragmentary View similar'to Figure 1, showing an alternative form of the invention.

Hi Figure 8 is an enlarged section taken on the line 8--8 of Figure '7.

- Referring more particularly to the drawings, A 10 is an upper lock chamber, B a lower lock chamber and C a culvert extending therebetween and having a gate valve D. The culvert C has an upper portion l8 communicating with the upper lock chamber A, a sharply inclined portion H and a lower portion 12' communicating with the lower lock chamber B.

' In the lower portion 12 adjacent the lower end of the inclined portion l l is placed a constriction i3 which may be formed of concrete, as shown in the drawings, but may be formed of metal or any other suitable material. The constriction I3 is shaped to correspond with the contour of the interior of the culvert and has a central passageway M extending therethrough, said passageway 5 being wider at its entrance than at its discharge end. Also placed in the lower portion l2 and spaced from the constriction I3 are one or more additional constrictions [5, one only being shown in the drawings. Each additional constriction 6 is provided with a central passageway I6, said passageway being somewhat larger than the passageway 14 of the first constriction referred to. In the case where more than one additional constriction I5 is employed the passageways 16 may either all be of the same size or they may be progressively increased in size towards the outlet of the lower portion l2 of the culvert. For the purpose of illustration the additional constriction I5 is shown as formed of metal but it may be replaced by a concrete structure.

Adjacent the discharge ends of each of the constrictions l3 and 15 are lateral passes l8 communicating with the lower lock chamber and the culvert. The culvert C may be of any shape but when the bottom thereof is substantially rectangular in cross section as shown in the drawings, said bottom is rounded as at H3 at the side of the culvert opposite the lateral passes 18 adjacent the constrictions l3 and I5.

An alternative form of constriction which may be used in place of the constriction i3 is shown in Figure 7. This constriction comprises a substantially wedge-shaped member 20, the apex of which is adjacent the lower end of the sharply The formation of thisvacuumis prevented by the additional constriction I 5 which, by causing, aback pressure, forces some of the water back to-'-' descending portion II. A restricted passageway 2| is'thus formed between the widest portion of the member and the wall of the culvert As stated above, the culvert C maybe of any shape, two difierent shapes being shown in the drawings by way of example. Referring to Figure 4, the culvert shown at 22 is higher and narrower than the culvert'shown at 23. In order to obtain the best results 'itis preferable to use the member 20in culvert 22 and the constriction IS in the culvert 23'. It maybe pointed out, howr ever, thzttlthis is not'necessary and that the two constrictions may be interchanged ifit is so desired. a V i While the device has been described as being used in a culvert extending between two lock V inclined portion.

" r Whenwa'te'r isrr ushing through the culvert,

- the constriction l3 or the mem'ber-2fl causes a chambers, it is'to be understood that it may be therein a' sharplyused in any culvert having The deviceloperates in the following manner:'

' back pressure-which extendsup intothe inclined 1 portion H, preventing the water 'from leaving the;

sides of the culvert, thus avoiding-theformation of a, vacuum in the inclinedportion. -Asgthe water is discharged through, the constriction I3,

whichlacts as a nozzle, a vacuum normally would be formed around thestream; on the side of the constriction remotegfrom' the inclined f portion.

wards the constriction 13. ht the same vtime, water entering the culvertthro'ugh the lateral pass J8 adjacent said constriction; is directed around the stream by the rounded portion l9, comf the restriction or restrictions {5 is avoided in the 1 samejmanner. t 1 v a P ,By' eliminating vacua in the culvert, air mixed I with the water cannot' explode from it and attack prcumulate in the lower'portion of the culvert causv V pletely filling the culvert at this point, 'thus'pre v'enting'the formation of a'vacuum'. The formation of a vacuum adjacent the discharge side'of the concrete of the culvert, nor will the air acingtremendous surges when the valves are closed.

;Also;, when there are-'nofvacua in the culvert waterhammer is eliminated.

From the, above it will be seen: that means have been providedwhich will prevent excessive wear on culverts.

Various; modific'atio s maywbe made in this invention without departing from the spirit" there ofior the scopeof the claims, and therefore the exact forms shown areto be taken as illustrative 7 member and thewall of the culvert.- V

the discharge side of the'constrictions. p

only and not in a limiting sense, and it is desired that only such limitations shall be placed there on as are disclosed in the prior art or are set forth in the accompanying claims. What I claim is:- 1 '1. In a liquid carrying culvert having a sharply inclined portion, means adjacent the lower end of said portion adapted to restrict the flow of liquid therethrough, thereby preventing the formation of a vacuum therein and means for causing a lback'pressureon the side of the first mentioned 7 means remote from said inclined portion.

2. In a liquid carrying culvert having a sharply v inclinedportion, at least two constrictions in the V culvert below said portions, and means foradmitting liquid into the culvert adjacent to'and' on the side of each of the constrictions remote from said inclined portion, thereby preventing the liquid flowing through the culvert from forming a vacuum at the discharge side of the con strictionsa 1 3. A device according to claim 1', inirwhichthe" means adapted to restrict the flow of the liquid comprises a substantially wedge-shaped member; 1'

V the apex of which is adjacent the lower end of" the descending portion; thus forming a restricted passageway between'the widest portion of said 4;;In a liquid carrying culvert extending tween two lockchambers andhaving a sharply 370' inclined portio-n a plurality of constrictions below said portions having restricted passageways Y therethrough, the passageway of the first co'nstriction being somewhat smaller =thanthe pas- 35 lateral pass adjacent the discharge; side or; each i constrictioncommunicating with one of the lock I sageway or passageways-of the remainde land a chambers. 1

5. A device according toclaim 4 wherein the,

restrictedpassageways thereof are progressively larger than the passageway of the first restric tion.

gular in cross-section, said bottom being rounded at the side opposite the lateral passes adjacent the r7. A'devic e accordingto claim 4 wherein substantiallyrectangular in cross I section, said bottom being rounded" at the side'opposite the lateral passes adjacent; the discharge side of the constrictions. V v

ROBERT A. BRADLEY.

6. A' devicetaccording. to claim 4 in which the bottom of the culvert is substantially rectan-V restricted passageways thereof are progressively f larger than the passageway of the first re'stric- 'tion and in which the bottom of the culvert is 

